Generally, an operator protects its customer resources by locking a network, hoping its customers can only use network resources stipulated by the operator itself, therefore, the operator requires higher and higher security of network locking of a terminal product.
The operator generally implements a requirement on the network locking of a terminal by limiting the terminal to use of only a stipulated data card, such as a SIM (Subscriber Identity Module, subscriber identity module) card.
In the prior art, a network locking solution for the terminal mainly includes:
1. When producing a terminal, a manufacturer writes a valid public land mobile network (PLMN) number segment, a locking flag and an unlocking code value into a certain Flash (flash) in a board of the terminal.
2. When a terminal user inserts a SIM card into the board of the terminal, the board firstly reads a PLMN number in the SIM card after powered up, and compares the read PLMN number with the PLMN number segment written into the foregoing Flash. If the read PLMN number belongs to the PLMN number segment written into the foregoing Flash, the locking flag is removed, the terminal is unlocked, and the terminal uses the SIM card normally; otherwise, the user is prompted to input an unlocking code.
3. After receiving the unlocking code input by the user, the board calculates a Hash value through an MD5 algorithm and compares the Hash value with the foregoing unlocking code value written into the Flash. If the two are the same, the locking flag is removed, the terminal is unlocked, and the terminal uses the SIM card normally; otherwise, the terminal cannot use the SIM card and the terminal is continuously locked.
In a process of implementing the present disclosure, the inventor finds that the network locking solution in the prior art at least has the following problems.
The solution only verifies the SIM card on a terminal side, the checking method is simple, and it is quite easy for a hacker to cheat the SIM card verification by setting a fake PLMN in a manner of a card sticker and the like in addition to the original PLMN number carried on the SIM card.
The network locking solution unlocks the terminal through the unlocking code, which is also easy to be cracked by a hacker, and the security is low.